In DSM-III, this disorder is called Multiple Personality
A. The existence within the individual of two or more distinct personalities, each of which is dominant at a particular time.
B. The personality that is dominant at any particular time determines the individual's behavior.
C. Each individual personality is complex and integrated with its own unique behavior patterns and social relationships.
Psychogenic Fugue and Psychogenic Amnesia may be confused with Multiple Personality, but do not present its characteristic repeated shifts of identity and usually are limited to a single, brief episode. Also, in both Psychogenic Amnesia and Psychogenic Fugue, awareness of the original personality is absent. Complex social activities, memories, behavior patterns, and friendships are not present in Psychogenic Amnesia and are uncommon in Psychogenic Fugue.
Psychotic disorders such as Schizophrenic Disorders may be confused with Multiple Personality because the individual reports hearing or talking with the voices of other personalities.
Malingering can present a difficult diagnostic dilemma. The presence of secondary gain suggests Malingering. Hypnosis or amytal interview may be of help in resolving especially difficult cases.
A. The presence of two or more distinct identities or personality states (each with its own relatively enduring pattern of perceiving, relating to, and thinking about the environment and self).
B. At least two of these identities or personality states recurrently take control of the person's behavior.
C. Inability to recall important personal information that is too extensive to be explained by ordinary forgetfulness.
D. The disturbance is not due to the direct physiological effects of a substance (e.g., blackouts or chaotic behavior during Alcohol Intoxication) or a general medical condition (e.g., complex partial seizures). Note: In children, the symptoms are not attributable to imaginary playmates or other fantasy play.
General Medical Conditions
Dissociative Identity Disorder must be distinguished from symptoms that are caused by the direct physiological effects of a general medical condition (e.g., seizure disorder). This determination is based on history, laboratory findings, or physical examination. Dissociative Identity Disorder should be distinguished from dissociative symptoms due to complex partial seizures, although the two disorders may co-occur. Seizure episodes are generally brief (30 seconds to 5 minutes) and do not involve the complex and enduring structures of identity and behavior typically found in Dissociative Identity Disorder. Also, a history of physical and sexual abuse is less common in individuals with complex partial seizures. EEG studies, especially sleep deprived and with nasopharyngeal leads, may help clarify the differential diagnosis.
Symptoms caused by the direct physiological effects of a substance can be distinguished from Dissociative Identity Disorder by the fact that a substance (e.g., a drug of abuse or a medication) is judged to be etiologically related to the disturbance.
The diagnosis of Dissociative Identity Disorder takes precedence over Dissociative Amnesia, Dissociative Fugue, and Depersonalization Disorder. Individuals with Dissociative Identity Disorder can be distinguished from those with trance and possession trance symptoms that would be diagnosed as Dissociative Disorder Not Otherwise Specified by the fact that those with trance and possession trance symptoms typically describe external spirits or entities that have entered their bodies and taken control.
Other mental disorders
Controversy exists concerning the differential diagnosis between Dissociative Identity Disorder and a variety of other mental disorders, including Schizophrenia and other Psychotic Disorders, Bipolar Disorder, With Rapid Cycling, Anxiety Disorders, Somatization Disorders, and Personality Disorders. Some clinicians believe that Dissociative Identity Disorder has been underdiagnosed (e.g., the presence of more than one dissociated personality state may be mistaken for a delusion or the communication from one identity to another may be mistaken for an auditory hallucination, leading to confusion with the Psychotic Disorders; shifts between identity states may be confused with cyclical mood fluctuations leading to confusion with Bipolar Disorder). In contrast, others are concerned that Dissociative Identity Disorder may be overdiagnosed relative to other mental disorders based on the media interest in the disorder and the suggestible nature of the individuals. Factors that may support a diagnosis of Dissociative Identity Disorder are the presence of clear-cut dissociative symptomatology with sudden shifts in identity states, reversible amnesia, and high scores on measures of dissociative and hypnotizability in individuals who do not have the characteristic presentations of another mental disorder.
Malingering and Factitious Disorder
Dissociative Identity Disorder must be distinguished from Malingering in situations in which there may be financial or forensic gain and from Factitious Disorder in which there may be a pattern of help-seeking behavior.
A. Disruption of identity characterized by two or more distinct personality states, which may be described in some cultures as an experience of possession. The disruption in identity involves marked discontinuity in sense of self and sense of agency, accompanied by related alterations in affect, behavior, consciousness, memory, perception, cognition, and/or sensory-motor functioning. These signs and symptoms may be observed by others or reported by the individual.
B. Recurrent gaps in the recall of everyday events, important personal information, and/or traumatic events that are inconsistent with ordinary forgetting.
C. The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
D. The disturbance is not a normal part of a broadly accepted cultural or religious practice. Note: In children, the symptoms are not better explained by imaginary playmates or other fantasy play.
E. The symptoms are not attributable to the physiological effects of a substance (e.g., blackouts or chaotic behavior during alcohol intoxication) or another medical condition (e.g., complex partial seizures).
The core of dissociative identity disorder is the division of identity, with recurrent disruption of conscious functioning and sense of self. This central feature is shared with one form of other specified dissociative disorder, which may be distinguished from dissociative identity disorder by the presence of chronic or recurrent mixed dissociative symptoms that do not meet Criterion A for dissociative identity disorder or are not accompanied by recurrent amnesia.
Individuals with dissociative identity disorder are often depressed, and their symptoms may appear to meet the criteria for a major depressive episode. Rigorous assessment indicates that this depression in some cases does not meet full criteria for major depressive disorder. Other specified depressive disorder in individuals with dissociative identity disorder often has an important feature; the depressed mood and cognitions fluctuate because they are experienced in some identity states but not others.
Individuals with dissociative identity disorder are often misdiagnosed with a bipolar disorder, most often bipolar II disorder. The relatively rapid shifts in mood in individuals with this disorder - typically within minutes or hours, in contrast to the slower mood changes typically seen in individuals with bipolar disorders - are due to the rapid, subjective shifts in mood commonly reported across dissociative states, sometimes accompanied by fluctuation in levels of activation. Furthermore, in dissociative identity disorder, elevated or depressed mood may be displayed in conjunction with overt identities, so one or the other mood may predominate for a relatively long period of time (often for days) or may shift within minutes.
Some traumatized individuals have both posttraumatic stress disorder (PTSD) and dissociative identity disorder. Accordingly, it is crucial to distinguish between individuals with PTSD only and individuals who have both PTSD and dissociative identity disorder. This differential diagnosis requires that the clinician establish the presence of absence of dissociative symptoms that are not characteristic of acute stress disorder or PTSD. Some individuals with PTSD manifest dissociative symptoms that also occur in dissociative identity disorder: 1) amnesia for some aspects of trauma, 2) dissociative flashbacks (i.e., reliving of the trauma, with reduced awareness of one's current orientation), and 3) symptoms of intrusion and avoidance, negative alterations in cognition and mood, and hyperarousal that are focused around the traumatic event. On the other hand, individuals with dissociative identity disorder manifest dissociative symptoms that are not a manifestation of PTSD: 1) amnesias for many everyday (i.e., nontraumatic) events, 2) dissociative flashbacks that may be followed by amnesia for the content of the flashback, 3) disruptive intrusions (unrelated to traumatic material) by dissociated identity states into the individual's sense of self and agency, and 4) infrequent, full-blown changes among different identity states.
Dissociative identity disorder may be confused with schizophrenia or other psychotic disorders. The personified, internally communicative inner voices of dissociative identity disorder, especially of a child (e.g., "I hear a little girl crying in a closet and an angry man yelling at her"), may be mistaken for psychotic hallucinations. Dissociative experiences of identity fragmentation or possession, and of perceived loss of control over thoughts, feelings, impulses, and acts, may be confused with signs of formal thought disorder, such as thought insertion or withdrawal. Individuals with dissociative identity disorder may also report visual, tactile, olfactory, gustatory, and somatic hallucinations, which are usually related to posttraumatic and dissociative factors, such as partial flashbacks. Individuals with dissociative identity disorder experience these symptoms as cause by alternate identities, do not have delusional explanations for the phenomena, and often describe the symptoms in a personified way (e.g., "I feel like someone else wants to cry with my eyes"). Persecutory and derogatory internal voices in dissociative identity disorder associated with depressive symptoms may be misdiagnosed as major depression with psychotic features. Chaotic identity change and acute intrusions that disrupt thought processes may be distinguished from brief psychotic disorder by the predominance of dissociative symptoms and amnesia for the episode, and diagnostic evaluation after cessation of the crisis can help confirm the diagnosis.
Symptoms associated with the physiological effects of a substance can be distinguished from dissociative identity disorder if the substance in question is judged to be etiologically related to the disturbance.
Individuals with dissociative identity disorder often present identities that appear to encapsulate a variety of severe personality disorder features, suggesting a differential diagnosis of personality disorder, especially of the borderline type. Importantly, however, the individual's longitudinal variability in personality style (due to inconsistency among identities) differs from the pervasive and persistent dysfunction in affect management and interpersonal relationships typical of those with personality disorders.
This disorder may be distinguished from dissociative identity disorder by the absence of an identity disruption characterized by two or more distinct personality states or an experience of possession. Dissociative amnesia in conversion disorder is more limited and circumscribed (e.g., amnesia for a non-epileptic seizure).
Individuals with dissociative identity disorder my present with seizurelike symptoms and behaviors that resemble complex partial seizures with temporal lobe foci. These symptoms include déjà vu, jamais vu, depersonalization, derealization, out-of-body experiences, amnesia, disruptions of consciousness, hallucinations, and other intrusion phenomena of sensation, affect, and thought. Normal electroencephalographic findings, including telemetry, differentiate non-epileptic seizures from the seizurelike symptoms of dissociative identity disorder. Also, individuals with dissociative identity disorder obtain very high dissociation scores, whereas individuals wiht complex partial seizures do not.
Individuals who feign dissociative identity disorder do not report the subtle symptoms of intrusion characteristic of the disorder; instead they tend to overreport well-publicized symptoms of the disorder, such as dissociative amnesia, while underreporting less-publicized comorbid symptoms, such as depression. Individuals who feign dissociative identity disorder tend to be relatively undisturbed by or may even seem to enjoy "having" the disorder. In contrast, individuals with genuine dissociative identity disorder tend to be ashamed of and overwhelmed by their symptoms and to underreport their symptoms or deny their condition. Sequential observation, corroborating history, and intensive psychometric and psychological assessment may be helpful in assessment.
Individuals who malinger dissociative identity disorder usually create limited, stereotyped alternative identities, with feigned amnesia, related to the events for which gain is sought. For example, they may present an "all-good" identity and an "all-bad" identity in hopes of gaining exculpation for a crime.